In general, for the cleaning of clothes, there are available wet cleaning in which cleaning is carried out with a neutral detergent using water as the medium, laundry cleaning in which cleaning is carried out with an alkaline detergent using water as the medium and dry cleaning in which an organic solvent is used as the medium. Clothes made of wool fabric such as suits and sweater, when cleaned by a method using water as the medium, are likely to shrink and/or lose original trim appearance. In addition, clothes made of silk fabric such as necktie and scarf, when cleaned by a method using water as the medium, are likely to lose surface gloss. For the reasons mentioned above in the majority of instances, clothes made of any of wool fabric and silk fabric are cleaned by means of dry cleaning which is less prone to cause a problem of shrinkage and the like.
There are available as an organic solvent to be used in dry cleaning, halogen base solvents such as tetrachloroethylene; 1,1,2-trichloro-1,2,2-trifluoroethane; 1,1,1-trichloroethane, and alternative solvents to flon (chlorofluorocarbon) exemplified by 1,3-dichloro-1,2,2,3,3-pentafluoropropane, 1,1-dichloro-1-monofluoroethane and the like in addition to a petroleum base solvent. In recent years however, there have been pointed out a variety of problems on the above-mentioned solvents from the viewpoint of influences on global environment and the ecosystem. That is to say, a petroleum base solvent, which is a substance responsible for air pollution, involves such a problem as dermal injury due to the residence thereof in the case of insufficiently dried clothes. Moreover, carcinogenicity of tetrachloroethylene is pointed out, whereby curtailment of an amount thereof to be used is required. Further, it has been decided since 1996 to entirely abolish the production of 1,1,2-trichloro-1,2,2-trifluoroethane and 1,1,1-trichloroethane each as an ozonosphere-depleting substance. Furthermore, it is decided to entirely abolish in 2020, the production of 1,3-dichloro-1,2,2,3,3-pentafluoropropane because of its concern for being a prospective ozonosphere-depleting substance.
On the other hand, accompanying improved standard of living in recent years, high grade-oriented clothes are enhanced, resulting in advanced diversification thereof. As a consequence, conventional dry cleaning system elutes the dyeing of clothes and/or impairs decorations such as buttons as the case may be. For the reasons mentioned above, attention has been paid to a silicone base solvent as a solvent for dry cleaning which never impairs diversified clothes and exerts less influence on the global environment and the ecosystem.
However a silicone base solvent, when used alone for cleaning, is not sufficient in detergency for dirt due to oil and fat and water-soluble dirt, and brings about the likelihood that the dirt once removed from clothes again sticks thereto. In addition, the silicone base solvent is inferior in detergency for water-soluble dirt such as sweat stain and spot stuck to trousers, skirts, collars of suits and the like. Even when there is used a pretreatment agent in which a surfactant is blended with water and an alcohol for the purpose of removing sweat stain and spot prior to dry cleaning, the silicone base solvent is prone to give rise to such a clothes trouble as annular stain on clothes owing to lack of its sufficient solubilizing power in water and at the same time, to impair softness and conformability of clothes after cleaning.
Such being the case, there is eagerly desired the development of a detergent composition which is used for dry cleaning and which brings about excellent properties in detergency, capability of preventing recontamination, solubilizing power in water and softness and conformability of clothes after cleaning by being added to a silicone base solvent.
There are disclosed a composition which is blended with a polyether modified silicone having a molecular weight of at most 3500 and a nonionic surfactant in Japanese Patent Application Laid-Open No. 59395/1993 (Hei 5); a composition which is blended with a cyclic polysiloxane and a nonionic surfactant of polyoxyalkylene series having a HLB value in the range of 2 to 10 in Japanese Patent Application Laid-Open No. 13095/1997 (Hei 9); and a composition which is blended with a cyclic polysiloxane, a surfactant and a hydrophilic solvent in Japanese Patent Application Laid-Open No. 176697/1997 (Hei 9). Nevertheless in the case where dry cleaning is carried out by adding any of the above-mentioned compositions in a silicone base solvent, a problem still remains unsolved in that capability of preventing recontamination and solubilizing power in water are insufficient, thus causing deterioration in softness and conformability of clothes and clothes trouble of annular stain after cleaning.